At the Windows 8 launch, Microsoft CEO Steve Ballmer highlighted the opportunities that the new OS offers to developers. Said he: "There are 670 million devices just waiting to be upgraded to Windows 8." And the way to reach their users, he said, is through the Windows Store, the sole distributor for Windows 8 apps. On top of that, Ballmer said, 400 million new PCs are expected to be sold over the next year. If those numbers prove true, Windows app developers would have a market in excess of 1 billion different devices. Apps designed for new Windows UI (confusingly known as Metro and Modern UI previously) are capable of running on both Windows 8 and Windows RT devices -- meaning the same app will behave similarly on a desktop, laptop, tablet or anything in between. With such a huge momentum behind Microsoft, it's almost impossible for developers to ignore the new market the platform creates. It's only a matter of time before great titles start to populate Windows Store, and they'll be tablet-optimized from day one. This, of course, directly challenges one of the main strengths of the iPad, which currently boasts the most tablet-optimized apps in its App Store. But for Android tablets  the opportunity window is closing fast, and I doubt Google can move fast enough to patch up the sorry state of the Play Store before Windows takes over as the No. 2 tablet platform, or even No. 1. As Ballmer said, "Welcome to the world of Windows 8." Image: TechCrunch